This is on a different topic. Ms. palat. 1066, c. 1420, provides us with a specific mythological association to the Charioteer, which is also that governing the "Mantegna" Sun card. In palat. 1066, the horses of the sun are painted reddish and whitish, as in the single card from Ferrara (mid-15th century), the Catelin Geoffrey (1557), and the Noblet (c. 1650).

The text relates, in connection with a different illumination of the solar chariot (see viewtopic.php?f=11&t=647), how Phaeton sought glory by guiding these horses, but fell from his chariot, landing in a river and dying. Similarly, in the tarot sequence, the charioteer is followed by the Wheel of Fortune, in which those who have ruled no longer rule (falling) and are without rule (at the bottom of the wheel).

However other drivers of the solar chariot obviously do better, since the sun usually follows its expected course.

In the Phaedrus myth, the Charioteer who is initially in the heavens is dragged to earth by his horses, a similar downward turn of the wheel, although less catastrophic.

I believe historically the Kings of Hearts in Playing cards has been Charlemangne.
He was a catholic and spread his faith throughout his Empire- He was also the first Holy Roman Emperor.
The above image is his shroud.
In Dante's Divine Comedy the spirit of Charlemagne appears to Dante in the Heaven of Mars among the other "warriors of the faith".

The Universe is full of magical things patiently waiting for our wits to grow sharper.
Eden Phillpotts

From a document we have another Florentine deck in Mantova mentioned in 1465 (an inventory).

There are some good reasons to date the deck between 1461-1465. Also we know, that the deck type occasionally was adapted to foreign interests and heraldic (Alessandro Sforza deck). And we know, that the Charles VI was not a single deck.

mikeh wrote:
For female charioteers, the PMB and CY are not alone. There is also the Issy and the minchiate. That the Issy's charioteer is surrounded by four female attendants, seems to me to say that she is the Quintessence. And when art presented nude females, as we see in the minchiate version, they were acceptable and honorable to view primarily if they represented the ideal, and even then preferably if they showed a modicum of modesty (as Venus often did not).

mikeh wrote:
For female charioteers, the PMB and CY are not alone. There is also the Issy and the minchiate. That the Issy's charioteer is surrounded by four female attendants, seems to me to say that she is the Quintessence. And when art presented nude females, as we see in the minchiate version, they were acceptable and honorable to view primarily if they represented the ideal, and even then preferably if they showed a modicum of modesty (as Venus often did not).